What is vitreoretinal degeneration?

Vitreoretinal Degeneration

Vitreoretinal degeneration is a group of conditions characterized by abnormal changes at the interface between the vitreous and retina, including retinal thinning, vitreous liquefaction, and firm vitreoretinal adhesions that can lead to retinal tears, detachments, and vision loss. 1, 2

Definition and Pathophysiology

Vitreoretinal degeneration encompasses several disorders affecting the vitreous-retinal interface, with the most common forms including:

• Lattice Degeneration: A peripheral vitreoretinal condition characterized by:

  • Retinal thinning
  • Overlying vitreous liquefaction
  • Firm vitreoretinal adhesions at the margins of thinning
  • Most lesions are ovoid with long axes parallel to the ora serrata
  • Round holes frequently occur within these areas 1

• Posterior Vitreous Detachment (PVD): Separation of the posterior vitreous cortex from the internal limiting membrane of the retina, which can be:

  • Complete or partial
  • Typically occurs between ages 45-65
  • May occur earlier in trauma and myopia
  • Can lead to vitreous traction at sites of vitreoretinal adhesion 1, 2

• Vitreomacular Traction (VMT): Partial vitreous separation from the retina resulting in mechanical distortion of the macula 1

Clinical Features and Symptoms

Patients with vitreoretinal degeneration may present with:

• Light flashes (photopsias): Most noticeable in dark environments, caused by vitreous traction on the retina
• Floaters (myodesopias): May be due to:
  • Blood from torn retinal vessels
  • Condensations of vitreous collagen
  • Epipapillary glial tissue (Weiss ring) torn from the optic nerve head
• Visual field defects: Particularly peripheral field loss if retinal detachment occurs
• Blurred vision: Especially if the macula becomes involved 1, 2

Types of Vitreoretinal Degenerations

1. Non-syndromic Forms

• Lattice degeneration
• Age-related PVD
• Wagner syndrome (WGN1) - associated with mutations in versican (CSPG2) 3
• Snowflake vitreoretinal degeneration (SVD) - associated with mutations in potassium channel (KCNJ13) 3

2. Syndromic Forms

• Stickler Syndrome: The most common inherited vitreoretinal disorder associated with retinal detachment 2, 3

  • Ocular features: high myopia, retinal membranes, lattice degeneration
  • Systemic features: skeletal dysplasia, marfanoid habitus, cleft palate
  • Autosomal dominant inheritance
  • Gene defects related to COL2A1 (type I) and COL11A1 (type II)

• Other connective tissue disorders: Various bone dysplasias with vitreoretinal degeneration, likely involving type II collagen abnormalities 4

Risk Factors for Complications

Factors that increase risk of progression to retinal tears and detachment:

• Age: PVD typically occurs between ages 45-65
• Myopia: Earlier onset of PVD
• Trauma: Can precipitate PVD
• Previous eye surgery: Especially cataract surgery
• Family history: Particularly for inherited forms
• Radial lattice degeneration: Higher risk than circumferential lattice 1, 2

Diagnosis

Diagnosis is primarily clinical through:

• Slit-lamp biomicroscopy: May show a prominent plane defining the posterior vitreous face
• Presence of Weiss ring: Strong evidence of PVD
• Indirect ophthalmoscopy with scleral depression: To examine the peripheral retina for lattice degeneration and retinal breaks 1

Clinical Significance and Complications

The most serious complication is rhegmatogenous retinal detachment (RRD):

• Between 8-22% of patients with acute PVD symptoms have a retinal tear at initial examination
• Patients with an acute PVD who have no detected breaks initially have a 2-5% chance of developing breaks in subsequent weeks
• Direct correlation between amount of vitreous hemorrhage and likelihood of retinal tear
• Approximately 80% of patients who later develop breaks had either pigmented cells, hemorrhage, or new symptoms at initial evaluation 1, 2

Management Approach

Management focuses on:

1. Identifying high-risk patients: Those with symptoms of acute PVD, vitreous hemorrhage, or lattice degeneration
2. Thorough examination: Complete dilated fundus examination with scleral depression
3. Follow-up: Patients with acute PVD symptoms but no detected breaks should be re-examined within 4-6 weeks
4. Treatment of retinal breaks: Prophylactic treatment of symptomatic retinal breaks to prevent retinal detachment
5. Patient education: Informing high-risk patients about symptoms of PVD, retinal breaks, and retinal detachments 1

Prognosis

The prognosis depends on:

• Timely detection and treatment of retinal breaks
• Whether the macula is involved in any retinal detachment
• The specific type of vitreoretinal degeneration
• Presence of associated systemic disorders 2

Early detection and treatment of retinal breaks significantly improves visual outcomes and reduces the risk of retinal detachment.